In recent decades, reinforced concrete piles have been widely used in the world in general and in Vietnam in particular for building up heavy duty works, those include jack piles, cast-in-situ piles, Barrettes piles, concrete driven piles.
Jack piles have low construction costs but jacking (driving) is causative of shaking to adjacent works. The strength of jack piles is limited. Particularly, long piles are made by means of many joints, which are easy to be ruined and consequently reducing the load-bearing capacity of piles. Further, the use of this kind of piles badly affects the boring for basement construction, during which pile heads are easy to be tilted and broken.
Cast-in-situ piles and Barrettes piles have higher strengths and fewer impacts on adjacent works. Nevertheless, the costs for making these piles are high. Furthermore, quality control during construction is complicated, particularly control of verticality of the bored holes.
In general, all the piles mentioned above have those backwards because of their simple shapes with circular or rectangular cross-sections. It is therefore necessary to make reinforced concrete piles with more complicated shapes in order to obviate the backwards. Nevertheless, that is currently required a process of many steps, more time and higher expenses. In practice, many piles have been made failing to meet technical requirements. For instance, a pile with T-shape cross-section needs to be made in two steps, each step for one point of the cross-section. For any pile with a cross-section, which includes some parts not perpendicular, for instance, piles with a three-pointed or Y-shape cross-section, it is much more difficult since it is not easy to bore a hole meeting requirements, or walls of the bored hole are not vertical, and eventually, the resultant piles fail to meet technical specifications.
It is, therefore, an object of the invention to provide a grab bucket that helps to make reinforced concrete piles of high strength.
Another object of the invention is to provide a grab bucket that helps to make reinforced concrete piles with less material.
Another object of the invention is to provide a grab bucket that help to reduce costs of human and time for making reinforced concrete piles.
A further object of the invention is to provide a grab bucket to make reinforced concrete piles of consistent quality.